Development and Validation of a Novel Mobile Application for Bone Age Assessment

Original Article

J Pediatri Endocrinol. 2023; 8(1): 1059.

Development and Validation of a Novel Mobile Application for Bone Age Assessment

Patel R; Bajpai A*; Mendpara H; Dave C; Mehta S; Mendpara P; Shukla R

Department of Pediatric Endocrinology, Regency Center for Diabetes Endocrinology & Research and Department of Pediatric Critical Care, Regency Hospital Limited, Kanpur, India

*Corresponding author: Bajpai A Department of Pediatric Endocrinology, Regency Center for Diabetes Endocrinology & Research, Regency City Clinic, Opposite PPN Market, Kanpur 208001, India. Tel- +919454081769 Email: dranurag.bajpai@gmail.com

Received: August 17, 2023 Accepted: September 28, 2023 Published: October 05, 2023

Abstract

Background: Despite its pivotal role, the use of bone age is limited due to a lack of physician expertise, time, and access.

Objective: To develop and validate a mobile application-based bone age assessment tool.

Study Design: The study involved the selection of standardized images (from 307 radiographs), delineation (90 radiographs), evaluation (200 radiographs) and incorporation of regions of interest on the application, and validation against the Tanner-Whitehouse 3 method by an expert (252 radiographs) and non-expert users (110 radiographs).

Results: The application-based assessment by expert users had an absolute standardized difference of 4.7 months (95% confidence interval; 4.2-5.2 months), a relative standardized difference deviation of 4.4% (3.9-4.9%), and similar intraindividual [2.8 (1.9-3.7) months versus 3.6 (2.8-4.5) months] and interindividual variation [4.2 (3.3-5.0) versus 4.2 (3.3-5.2) months] compared to the TW3 method. Non-expert user assessment had an absolute standardized difference of 6.7 months (5.6-7.7 months) and a relative standardized difference deviation of 5.8% (4.7-6.9%). The mean test time was lower for application than TW3 for both expert [1.3 (0.2) versus 3.1 (1.0) minutes, p<0.001] and non-expert users [2.8 (1.0) versus 5.0 (1.4) minutes, p<0.001].

Discussion: Our study confirms the accuracy of mobile application-based bone age assessment. This, along with good precision, reduced complexity, and lower time requirement, suggests a potential for its widespread implementation.

Keywords: Bone age; Mobile application; Tanner whitehouse 3; Validation

Introduction

Bone age assessment is integral to Pediatric Endocrine evaluation [1]. Despite its significance, the use of bone age is limited in pediatric practice due to a lack of physician expertise, time, and accessibility. Bone age assessment methods use automated (BoneXpert) or manual comparison of the entire non-dominant hand (Greulich-Pyle) or specific regions of interest (Tanner-Whitehouse III method) with age and gender-specific standards [2-4].

Manual bone age assessment methods compare the whole radiograph (holistic approach; GP atlas) or a combination of regions of interest (analytical approach; TW3) to age and gender standards. The epiphyseal maturation of regions of interest varies in an individual making the perfect match between radiographs challenging. The analytical approach has higher precision than the holistic approach, as indicated by lower intra-observer variability for the TW method than the GP atlas [5].

These methods are complicated by the need for multiple sites that increase procedure time and variability. The need for morphological grading of each region of interest makes the TW3 method challenging for physicians with limited exposure to bone age assessment. Inconsistent interpretations of the capitate, hamate, the first distal, and fifth middle phalanx, part of the TW3 RUS method, have been reported [6]. Including epiphysis from similar regions contributes little to the diagnostic accuracy of a method while increasing its complexity. A higher number of regions of interest increases the test time and complexity of the method; making a reduction in the number of sites desirable. This highlights the need for an accessible tool allowing rapid bone age assessment with reduced complexity.

The availability of smart mobile phones provides an opportunity to allow point-of-care bone age assessment. We have developed mobile application tools guiding the evaluation and management of children with short stature and diabetic ketoacidosis [7,8]. We, therefore, aimed to develop a mobile application-based tool with a reduced number of regions of interest to allow simplified, reproducible, and valid bone age assessment.

Material and Methods

The study involved the selection of age and gender-specific standard images, delineation, evaluation, and incorporation of regions of interest on the mobile application, development of the regression equation for bone age interpretation, validation against the gold standard, and comparison with the automated method of bone age assessment (Bone Xpert) (Figure 1).